Infusion pump



June 16, 1964 G. w. HAHN 3,137,242

INFUSION PUMP Filed Jan. 22, 1962 2 Sheets-Sheet 1 4g I d@ fz /4 55 Zi Z9 .30 INVENTOR FigI 2 Z2 ya; l George WHahn G. w. HAHN 3,137,242

INFUSION PUMP 2 Sheets-Sheet 2 m, f M f a e June 16, 1964 Filed Jan. 22, 1962 1 l... ...MEF-3G52 United States Patent O 3,137,242 INFUSIN PUMP George William Hahn, 1605 Pentagon Parkway, Dallas, Tex. Filed Jan. 22, 1962, Ser. No. 167,820 3 Claims. (Cl. 103-152) This invention relates to lluid pumps of the type generally referred to as infusion pumps, and it has particular reference to surgical pumps utilized to inject fluid intravenously in the treatment of diseases, such as cancer, malnutrition, and the like, and the infusion of blood plasma, and other uids into the blood istream.

A prime object of the invention resides in the provision of a pump by which a medicament, such as methotrexate, can be injected Iinto the arteries, in the treatment of malignant diseases, from a reservoir at predetermined rates and pressures without contamination.

Pumps of the type described have been in general use for several years, and include such elements as radially arranged tensioned rollers in an annular chamber and engaging a exible tube to induce a iluid flow for a variety of purposes. However, such known devices are lacking in many of the features which will become apparent in the improvements hereinafter described, particularly in respect to the extreme accuracy and precision necessary in the application of such improvements in the treatment of diseases. i

An important object of the invention is that of providing a pump of the character described in which fluids, such as medicaments, can be injected into the arterial system from a reservoir in carefully measured quantities at constant pressures, and regulated in accordance with blood pressures encountered.

A further object of the invention resides in the provision of an infusion pump having a variable speed, which is highly desirable in the treatment of malignancies, such as cancer, due to the necessity for extreme accuracy in the injection of carefully measured quantities of medicaments during prolonged periods of time.

It is also an object of the invention to provide an infusion pump which is simple in design and structure, and thoroughly dependable in operation, and by which any type of liquids can be transmitted thereby in a constant, uninterrupted ow, without the intermittent surging and pulsations attributable to many conventional pumps designed for similar purposes.

Broadly, the invention contemplates the provision of a iluid pump by which various types of liquids can be moved in accurately measured quantities, at various constant speeds, depending upon the pressures required, and Without subjecting the liquid products to contamination, utilizing a flexible conduit which can be maintained under accurately predetermined and constant pressure.

While the foregoing objects are paramount, other and lesser objects will become manifest as the description proceeds, taken in connection with the appended drawings wherein:

FIGURE 1 is a front elevational View of a pump em bodying the invention, showing the tensioned roller arms operating in an annular recess.

FIGURE 2 is a transverse sectional view, on line 2--2 of FIGURE l, through the gear housing and the annular roller recess, illustrating the variable speed motor, the rheostat control and the gear assembly.

FIGURE 3 is a side elevational view of the invention, showing the motor and control knobs.

FIGURE 4 is an enlarged fragmentary illustration of one yof the roller arms, and roller impinging the flexible tube, the latter and the housing being shown partially in section.

3,137,242 Patented June 16, 1964 ICC FIGURE 5 is a fragmentary sectional view, on line 5 5 of FIGURE 4, showing a roller compressing the tube in the groove formed peripherally of the annular recess in the housing, and

FIGURE 6 fragmentarily illustrates a modified arrangement of tensioning springs for the roller arms.

Accordingly, referring to the drawings, apparatus embodying the invention is mounted on a base member 10 having a relatively thin housing 11 supported vertically along one side, as shown in FIGURES l', 2 and 3. A panel 12 is `arranged along an edge of the base 10 at right angles to the housing 11, and these elements are preferably formed of a plastic material.

Formed in the face plate 13 on the housing 11 is a circular opening 14 about the inner surface of which is defined a channel 15 adapted to receive a ilexible cornpressible tube 16 of plastic, or other suitable material, as shown best in FIGURES l and 4. A pair of grooves 17 are formed in the face plate 13 of the housing 11 which communicate with the channel 15 and extend vertically into the top of the face plate 13, as illustrated in FIGURE l, and receive the inlet and outlet portions 18 and 19 of the tube 16 which are retained in the grooves 17 by pins 20, or other suitable devices.

A disk 21 is mounted for rotation concentrically of the circular recess or opening 14 on a shaft 22 which is sup ported in bearings 23 and 24 pressed into annular recesses 25 and 26, respectively, in the front and rear walls 27 and 28 of the housing 11, as shown in FIGURE 2. A plurality of arms 29 are pivoted at a intermediate their ends about the disk 21 near its perimeter, and are equidistantly spaced, and each arm 29 has a roller 30 pivoted to its outer end adapted to engage and compress the tube 16 under the tension of an endless pull spring 31, in the manner shown in FIGURE l.

The inner end of each of the arms 29, opposite the roller 30 thereon, has a pulley 32 pivotally attached there to and rotates on a screw 33, and the spring 31, which is in the form of a belt, is passed over each of the pulleys 32 and exerts an equal tension on the arms 29, whose fulcrums a are intermediate their ends, whereby the rollers 30 are caused to bear against the tube 16 with equal predetermined pressure. The disk 21 is rotated clockwise, as indicated by the arrow, so that uid from a reservoir (not shown) entering that portion of the tube 16 through the inlet portion 18, is moved around that portion of the tube 16 lying in the circular channel 15 by the pressure of the rollers 30 thereon, and out through the outlet portion 19 of the tube 16 in a constant, non-pulsating flow.

In the space 34 defined between the front and rear walls 27 and 28 is a relatively large gear 35 arranged in the shaft 22, and is secured to the latter by an integral collar 36 through the medium of a set screw 37, as shown in FIG- URE 2. The gear 35 is meshed with a smaller gear 38 on the shaft 39 of a motor 40 mounted by screws 41 on the back of the rear wall 28 of the housing 11.

The motor 40 is of the variable speed type and is controlled by a rheostat 42 on the panel 12 through the knob 43. A manual switch 44 is connected into the motor circuit and is also mounted .on the panel 12, as well as a fuse 46 and a jack plug receptacle 46 by which the motor circuit is connected through a transformer (not shown) to a service outlet.

It is very important that the motor 40 be capable of variable speeds, and accurately controlled, in order that it mayI be readily adjusted to ioperate the pump at the proper speed to suit the type and rate of medication required to be injected or infused into the arterial system of a patient. It is also important that the speed of the motor 40 be constant when the rheostat 42 is properly adjusted.

ademas In FIGURE 6 is a fragmentarily illustrated in a moditied arrangement of the spring tensioning means for the arms 29 by which the rollers 30 are held in engagement with the tube 16. In this structure a plurality of individual springs 47 are provided whose ends are secured to the screws 33 on the inner ends of the arms 29. T his arrangement, while capable of maintaining a constant pressure on the tube 16 when each spring 47 has a uniform pull, the endless spring 31 is more dependable for uniformity and flexibility, particularly since the rollers 32 will provide for equalization of tension between the arms 29 and pressure on the tube 16 will not be relaxed at any point due to weakening of a spring 4'7 by fatigue or other cause.

The assembly is adapted to be supported on a table surface by legs 48 attached to the base 1t), or may be suspended on a rack or other supporting means, and cornpletely enclosed in a cabinet of any suitable design.

The invention, while described with great particularity, is capable of certain changes and modifications from time to time, by persons skilled in the art, without departing from the spirit and intent thereof or the scope of the appended claims.

What is claimed is:

1. In an infusion pump for medicaments having a base plate and a pair of vertical parallel walls along one side defining a housing, and a vertical panel arranged along an end of said base at right angles to said housing, the combination comprising, a face panel on the outer wall of said housing having a circular recess therein and a groove formed peripherally of said recess, a flexible tube arranged in said groove and having fluid inlet and outlet ends, a circular disk rotatively mounted concentrically of said recess, a plurality of arms pivotally attached intermediate their ends to said disk about the periphery thereof, and a roller pivoted to the outer end of each of said arms engageable with said tube in said groove to compress said tube progressively about said groove, a pulley pivoted on the inner end of each of said arms, an endless pull spring collectively embracing said pulleys connecting the inner ends of said arms for exerting tension thereon, and a vari- 4. able speed motor for rotating said disk and said arms thereon.

2. In an infusion pump of medicaments, having a base, a housing having a circular recess in its outer wall, a peripheral groove in said recess, and a variable speed "motor for driving said pump, the structure comprising, a disk rotatably mounted concentrically of said recess, a flexible flow tube adapted to lie in said peripheral groove in said recess, a plurality of arms spaced about the said disk and pivoted thereto intermediate their ends whereby their longitudinal axes are tangential to the axis of said disk, a roller attached to the outer end of each of said arms and engaging said flexible tube to compress the same progressively about said groove, a pulley pivotally arranged on the inner end of each of said arms, and an endless pull spring arranged about said pulleys whereby to exert pressure on said tube.

3. An infusion pump for injecting medicaments into the arterial system, a base element, and a housing thereon having a circular recess in a wall thereof, and a groove formed peripherally of said recess, and a compressible tube arranged in the groove in said recess having connection with a fluid source, the improvements comprising, a Sdisk rotatable concentrically of said recess and having means for rotating the same, a plurality of arms pivoted intermediate their ends about the outer edge of said disk, each having a roller pivoted to its outer end and engageable with said tube, a pulley on the inner end of each of said arms opposite said rollers, and a pull spring arranged about said pulleys operatively connecting the inner ends of said arms and exerting collective tension thereon whereby said rollers progressively compress said tube along said groove.

References Cited in the ile of this patent UNITED STATES PATENTS 87,837 Gilmore Mar. 16, 1869 1,988,337 Santiago et al Jan. l5, 1935 2,314,281 Knott Mar. 16, 1943 `2,695,117 Daniels Nov. 23, 1954 

1. IN AN INFUSION PUMP FOR MEDICAMENTS HAVING A BASE PLATE AND A PAIR OF VERTICAL PARALLEL WALLS ALONG ONE SIDE DEFINING A HOUSING, AND A VERTICAL PANEL ARRANGED ALONG AN END OF SAID BASE AT RIGHT ANGLES TO SAID HOUSING, THE COMBINATION COMPRISING, A FACE PANEL ON THE OUTER WALL OF SAID HOUSING HAVING A CIRCULAR RECESS THEREIN AND A GROOVE FORMED PERIPHERALLY OF SAID RECESS, A FLEXIBLE TUBE ARRANGED IN SAID GROOVE AND HAVING FLUID INLET AND OUTLET ENDS, A CIRCULAR DISK ROTATIVELY MOUNTED CONCENTRICALLY OF SAID RECESS, A PLURALITY OF ARMS PIVOTALLY ATTACHED INTERMEDIATE THEIR ENDS TO SAID DISK ABOUT THE PERIPHERY THEREOF, AND A ROLLER PIVOTED TO THE OUTER END OF EACH OF SAID ARMS ENGAGEABLE WITH SAID TUBE IN SAID GROOVE TO COMPRESS SAID TUBE PROGRESSIVELY ABOUT SAID GROOVE, A PULLEY PIVOTED ON THE INNER END OF EACH OF SAID ARMS, AN ENDLESS PULL SPRING COLLECTIVELY EMBRACING SAID PULLEYS CONNECTING THE INNER ENDS OF SAID ARMS FOR EXERTING TENSION THEREON, AND A VARIABLE SPEED MOTOR FOR ROTATING SAID DISK AND SAID ARMS THEREON. 